/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.zookeeper.test;

import java.io.IOException;
import java.util.Collections;
import java.util.List;

import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.ZooDefs.Ids;
import org.apache.zookeeper.data.Stat;

public class SledgeHammer extends Thread implements Watcher {
	/**
	 * @param args
	 * @throws IOException
	 * @throws KeeperException
	 * @throws NumberFormatException
	 */
	public static void main(String[] args) throws NumberFormatException, IOException {
		if (args.length != 3) {
			System.err.println("USAGE: SledgeHammer zookeeper_server reps reads_per_rep");
			System.exit(3);
		}
		SledgeHammer h = new SledgeHammer(args[0], Integer.parseInt(args[1]), Integer.parseInt(args[2]));
		h.start();
		System.exit(0);
	}

	int count;

	int readsPerWrite;

	ZooKeeper zk;

	public SledgeHammer(String hosts, int count, int readsPerWrite) throws IOException {
		zk = new ZooKeeper(hosts, 10000, this);
		this.count = count;
		this.readsPerWrite = readsPerWrite;
	}

	public void process(WatchedEvent event) {
		synchronized (this) {
			notifyAll();
		}
	}

	public void run() {
		try {
			Stat stat = new Stat();
			String path = zk.create("/hammers/hammer-", new byte[0], Ids.OPEN_ACL_UNSAFE,
					CreateMode.PERSISTENT_SEQUENTIAL);
			byte tag[] = (path + " was here!").getBytes();
			synchronized (this) {
				String startPath = "/hammers/start";
				System.out.println("Waiting for " + startPath);
				while (zk.exists(startPath, true) == null) {
					wait();
				}
				System.out.println("Running");
			}
			for (int i = 0; i < count; i++) {
				try {
					System.out.print(i + "\r");
					List<String> childs = zk.getChildren("/hammers", false);
					Collections.shuffle(childs);
					for (String s : childs) {
						if (s.startsWith("hammer-")) {
							s = "/hammers/" + s;
							zk.setData(s, tag, -1);
							for (int j = 0; j < readsPerWrite; j++) {
								zk.getData(s, false, stat);
							}
							break;
						}
					}
				} catch (KeeperException.ConnectionLossException e) {
					// ignore connection loss
				} catch (KeeperException e) {
					e.printStackTrace();
				}
			}
			System.out.println();
			zk.close();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

}
